Abstract: ROBOSIM was developed first in a VAX environment. Using PC's with a terminal program capable of emulating a TEKTRONIX 4014, students can create robots, see them graphically, and write control routines for them. ROBOSIM has been used as part of a course on robot manipulators. This package has been used to model many different commercial robots. Uses include simulation of a down-hand welding algorithm, a two-armed workcell, and even a robot positioner to be used in surgery. The system has also been implemented on an HP-9000 workstation equipped with an SRX graphics accelerator. The user interface of the system now contains a menu- and icon-based facility, as well as the original ROBOSIM language.